This new spring kit uses a round wire, cylindrical nano peened spring that drops right in with the OEM locator/seat. The CNC machined titanium retainers remove weight VS the OEM steel retainer for added durability and longevity to the valvetrain. Rev safely to 8200RPM and 32PSI of boost using either an S1 or S2 profile with piece of mind.

Sold as a set of 16.

Shim Over or shimless Spec:
Pressure @ Spring Height
73Lbs @ 1.345"
188lbs @ .945"

Shim under Spec:
70Lbs @ 1.345"
185lbs @ .954"